EXOGENOUS SERIES-NEEDLELEAF WOODS. 161 



Douglas Spruce, Douglas Fir. \ Pseudotsu 8 a 



\ Pseudolsuga Douglam Carr. 



Nomenclature. (Sudworth. ) 



Oregon Pine (Cal., Wash., Douglas Tree, Cork-barked 



Oreg.). Douglas Spruce. 



Red Fir, Yellow Fir (Oreg., Spruce, Fir (Mont.). 



Wash., Idaho, Utah, Mont., Red Pine (Utah, Idaho, Col.). 



Col.). Puget Sound Pine (Wash.). 

 Locality. 



Pacific coast region, Mexico to British Columbia. Best in 

 western Oregon and Washington. 



Features of Tree. 



One hundred and seventy-five to sometimes three hundred feet 

 in height, three to five and sometimes ten feet in diameter. 

 Older bark rough-gray, often looking as though braided. 



Color, Appearance, or Grain of Wood. 



Heartwood light red to yellow, scant sapwood nearly white. 

 Comparatively free from resins, pronounced variable rings 

 (four to forty per inch). 



Structural Qualities of Wood. 



Variable, usually hard, strong, difficult to work, durable. Splits 

 easily. 



Representative Uses of Wood. 



Heavy construction, dimension timbers, railway ties, piles, fuel. 



Weight of Seasoned Wood in Pounds per Cubic Foot. 



32 (U. S. Forestry Div.).* 



36 (average of 20 specimens by Soule).f 



32- 

 Modulus of Elasticity. 



1,680,000 (average of 41 tests by U. S. Forestry Div.).* 



1,862,000 (average of 21 specimens by Soule).f 



1,824,000. 



Modulus of Rupture. 



7,900 (average of 41 tests by U. S. Forestry Div.).* 

 9,334 (average of 21 specimens by Soule).f 



12,500. 



Remarks. 



Used similarly to hard pine. Lumbermen divide into red and 

 yellow woods, the former dark and coarse, the latter hne, 

 lighter, and more desirable. These distinctions probably due 

 to age. One of the world's greatest trees. 



f Professor Frank Soule, University of California. Trans. Am. List M. E., 

 p. 552, Vol. XXIX. 



